Trevithick's stationary high-pressure
expansive steam condensing whim-engine, erected at Cook's Kitchen mine in 1800. It worked at 172kN per sq m (35psi), had a 480mm diameter cylinder and a 1.52m stroke — and it was still working in 1870. The cylindrical boiler Trevithick designed for this engine soon became known as a 'Cornish boiler'.